From 1b863c350ba1f9b8ad1cb458df514ab0fe6bb127 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Lo=C3=AFc=20Hoguin?= Date: Mon, 11 Dec 2017 11:27:17 +0100 Subject: Add documentation for Cowboy 2.2 --- .../en/cowboy/2.2/manual/cowboy_handler/index.html | 233 +++++++++++++++++++++ 1 file changed, 233 insertions(+) create mode 100644 docs/en/cowboy/2.2/manual/cowboy_handler/index.html (limited to 'docs/en/cowboy/2.2/manual/cowboy_handler/index.html') diff --git a/docs/en/cowboy/2.2/manual/cowboy_handler/index.html b/docs/en/cowboy/2.2/manual/cowboy_handler/index.html new file mode 100644 index 00000000..687f67be --- /dev/null +++ b/docs/en/cowboy/2.2/manual/cowboy_handler/index.html @@ -0,0 +1,233 @@ + + + + + + + + + + + + Nine Nines: cowboy_handler(3) + + + + + + + + + + + + + + +
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cowboy_handler(3)

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Name

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cowboy_handler - Plain HTTP handlers

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Description

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The cowboy_handler middleware executes the handler selected +by the router or any other preceding middleware.

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This middleware takes the handler module and initial state +from the handler and handler_opts environment values, +respectively. On completion, it adds a result value to +the middleware environment, containing the return value +of the terminate/3 callback (if defined) and ok otherwise.

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This module also defines a callback interface for handling +HTTP requests.

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Callbacks

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Plain HTTP handlers implement the following interface:

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init(Req, State) -> {ok, Req, State}
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+terminate(Reason, Req, State) -> ok  %% optional
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+Req    :: cowboy_req:req()
+State  :: any()
+Reason :: normal
+        | {crash, error | exit | throw, any()}
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These two callbacks are common to all handlers.

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Plain HTTP handlers do all their work in the init/2 +callback. Returning ok terminates the handler. If no +response is sent, Cowboy will send a 204 No Content.

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The optional terminate/3 callback will ultimately be called +with the reason for the termination of the handler. +Cowboy will terminate the process right after this. There +is no need to perform any cleanup in this callback.

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The following terminate reasons are defined for plain HTTP +handlers:

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+normal +
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+ The connection was closed normally. +

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+{crash, Class, Reason} +
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+ A crash occurred in the handler. Class and Reason can be + used to obtain more information about the crash. The function + erlang:get_stacktrace/0 can also be called to obtain the + stacktrace of the process when the crash occurred. +

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Exports

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The following function should be called by modules implementing +custom handlers to execute the optional terminate callback:

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See also

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cowboy(7)

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+ Cowboy + 2.2 + Function Reference + +

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Navigation

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Version select

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+ + + + + + + + + -- cgit v1.2.3